Carl Alvar Wirtanen (November 11, 1910, Kenosha, Wisconsin – March 7, 1990 Santa Cruz, California) was an American astronomer who worked at Lick Observatory.
He discovered periodic comet 46P/Wirtanen, as well as eight asteroids, including notably the Apollo asteroid (29075) 1950 DA, which may have a non-negligible probability of impacting the earth in the year 2880. He also discovered two other Apollo asteroids: 1685 Toro and 1863 Antinous. The Shane Wirtanen Catalogue, a count of galaxies, was his major work published in 1954. He was of Finnish ancestry.
- ^ Brown, Michael E.; Groth, Edward J. (1989). "The Shane Wirtanen counts: Observability of the galaxy correlation function". Astrophysical Journal 338: 605. Bibcode:1989ApJ...338..605B. doi:10.1086/167222.
- ^ Klemola, Arnold Richard (1991). "Obituary: Carl Alvar Wirtanen, 1910–1990". Bulletin of the American Astronomical Society 23: 1495. Bibcode:1991BAAS...23.1495K.